An Intellectual Property Management and Protection (IPMP) tool is an object module having a content protection function such as authentication, encryption, watermarking and the like, and processes media data, and critical data such as key information. Accordingly, most service providers own dedicated IPMP tools and are reluctant to release information about the tools (functions, API, etc.) to the public.
The broad definition of an IPMP tool includes an IPMP tool for concealing data in a secure format to protect a copyright or guaranteeing data authenticity, and an encoder/decoder tool for simply encoding/decoding data in a specific format in order to give various multimedia effects to content data or increase compression/transmission efficiency. Information about the encoder/decoder tool (functions, API, etc.) may be made available to the public. The IPMP tool referred to herein is to be interpreted in the broad sense of the term.
Meanwhile, each broadcasting station applies at least one IPMP tool to its broadcast content in order to protect the broadcast content and/or give various multimedia effects to the broadcast content. A group of IPMP tools needed to provide such specific broadcasting service is defined as a tool group.
Each broadcasting station processes bare data of broadcast content using selected tools to generate a content packet, and transmits it to each user via a transmitting means. The content packet is finally delivered to a content player of the user. For example, it is assumed that broadcasting station A forms a content packet using tools a, b and c, and broadcasting station B forms a content packet using tools c, d, e and f. The content conforms to the MPEG-2 standard, and the content player has an IPMP terminal according to the MPEG-2 standard.
In this case, because each broadcasting station uses individual tools to protect content, the IPMP terminal needs to recognize all interface messages which may differ for the individual tools in order to guarantee interoperability. That is, if a new tool is developed and a new interface message for the tool is necessary, a conventional IPMP terminal should be greatly changed.
Further, when the IPMP terminal desires to use individual tools, it needs to recognize information about the tools, information indicating a control point where the tools operate, and information about functions of the tools (generally, disclosed to the public through an interface message).
However, while designers of content execution devices would like to have tool specifications disclosed to the public, tool developers oppose such public disclosure because it degrades security of the tools. This is because, when a number of tools are applied to one type of content, the tools themselves and a time point at which each tool is applied are exposed, and if each tool is easily hacked, the security of a final content packet is greatly degraded. Accordingly, there is an antinomic problem between content execution device designers and tool developers.
Further, the content execution device needs to have the tools a, b and c in order to execute the content of broadcasting station A, and the tools c, d, e and f in order to execute the content of broadcasting station B. Thus, it is necessary to access each broadcasting station on occasion, check whether there is a change in a used tool group, and adjust the tools of the content execution device according to the changed tool group. There are a great number of multimedia encoding/decoding tools and security tools. Accordingly, since content players require many tools, manufacturing cost increases and users are occasionally required to update tools of each broadcasting station.